The present invention relates to a growth enhancing additive to compound feed, containing an organic or inorganic acid, or salts thereof, with a beneficial effect on the treatment of compound feed, and a spent sulphite liquor from an acidic or neutral cellulose sulphite cooking.
It is known that the addition of acid to compound feed for pigs has an efficacious effect on their growth and health. Further, the acid addition to compound feed reduces the amount of consumed compound feed per kg of growth without the increased growth affecting the quality of the meat, since the percentage of meat remains relatively unchanged. This also saves on feed costs by reducing the feeding period and promoting better housing utilization.
The quality of the feed is also improved, as the acid kills undesirable bacteria and microorganisms in the feed.
The efficacious effects on pigs of adding acid to the compound feed with which they are fed is due to the beneficial effect that it has on the digestive system. The addition of acid inhibits the activity of and kills unfavorable and undesirable bacteria in the digestive tract of the pig. This results in a generally healthier environment in the stomach and intestinal tract of the pig. The natural bacterial intestinal flora achieve balance; the result is fewer digestive disorders, less diarrhea, and more compact manure. A low pH in the stomach also promotes an increase in the secretion of important digestive enzymes such as pepsin. This enzyme is important in the digestion of proteins. Increased pepsin secretion results in better digestion and protein utilization and thus to enhanced growth. At present there are compound feed products on the market, including Felleskjpet""s xe2x80x9cFormatxe2x80x9d, that exploit this principle.
It is also known that for other types of products, such as silage agents, it has been suggested that acids be used, along with spent sulphite liquor (SSL) as silage additive for grass, grain, masque etc., especially for preserving the protein content of the feed (Norwegian Patent No. 803321). Likewise, in European Patent Application A0043202, it has been suggested that an aqueous composition of sulphite spent sulphite liquor or lignosulphonate, organic acids and formaldehyde be used to treat animal feed containing protein or carbohydrate, in order to prolong the preservation of the feed.
Organic acids such as formic acid, acetic acid, etc. are customarily used as acid additives to compound feed.
There are a number of problems, however, with using strong acids such as formic acid, including the corrosion of equipment and exposure for those handling the product. There is considerable corrosion on storage tanks, mixing equipment, the production line for pelleted feed in particular. This drives up the operating costs and leads to the added burden of increased maintenance and system monitoring. Formic acid is corrosive to the skin and can cause damage from burning, which is why it is necessary to work with full body protection. During pelletising the temperature rises to 80-95xc2x0 C., which leads to the evaporation of some of the formic acid, the vapors of which are very dangerous on inhalation.
Another, purely practical problem arises in the many cases in which feed mills and breeders lack the equipment for dosing liquids.
In the present invention the above-mentioned problems associated with the use of acid additives in compound feed by adding a spent sulphite liquor from acidic or neutral cellulose sulphite cooking have been reduced. The spent sulphite liquor from acidic or neutral cellulose sulphite cooking is highly effective in reducing corrosion. It has also been shown that the amount of acid used can be reduced compared to the amounts used previously. A reduction in the amount of acid and the addition of the aforementioned spent sulphite liquor is expected to resolve the problem with evaporation of the acid in the manufacture of compound feed. If, in addition, the spent sulphite liquor is adsorbed on a carrier, further improvement is obtained. By adsorption of the spent sulphite liquor on a carrier, a dry product is attained which, in turn, can overcome the problem of feed mills and breeders not having the systems for liquid dosing.
Surprisingly, however, it has also been shown that the additive has a positive effect, beyond that of pure formic acid, on the growth of pigs. Studies show that a synergistic effect is obtained by using both formic acid and lignosulphonate, despite the fact that the concentration of formic acid is reduced.
The present invention includes a growth enhancing additive to compound feed that contains an organic or inorganic acid, or salts thereof, with a beneficial effect on the treatment of compound feed, and spent sulphite liquor from an acidic or neutral cellulose sulphite cooking. The spent sulphite liquor has a pH value in the range of 1 to 10. The base used to produce the spent sulphite liquor is either calcium, sodium, ammonia or magnesium.
The organic or inorganic acids with a beneficial effect on the treatment of compound feed are formic acid, acetic acid, propionic acid, citric acid, hydrochloric acid, phosphoric acid or mixtures thereof, formic acid being particularly preferred.
The salts of these acids are ammonium salts, alkaline and/or alkaline earth metal salts, especially NH4xe2x80x94, Naxe2x80x94, Caxe2x80x94 or Mgxe2x80x94.
By spent sulphite liquor from an acidic or neutral cellulose sulphite cooking is meant the spent sulphite liquor produced by treating timber with an aqueous liquid to which has been added sulphur dioxide and the aforementioned cations ammonia, sodium, calcium or magnesium. The main ingredient in the resulting spent sulphite liquor, after the separating out of cellulose, is lignosulphonate. In addition, there are mono and polymer sugars and inorganic salts.
The acidic or neutral cellulose sulphite spent sulphite liquor can also be adsorbed on a suitable carrier in order to obtain a dry substance. By carrier is meant a dry particulate. Such a material, for example, might be one of the ingredients in compound feed, e.g. soy meal or a water adsorbing silicate.
The additive contains an organic or inorganic acid, or salts thereof, with a beneficial effect on the treatment of compound feed, in an amount ranging from 10-90 percentage weight, and a spent sulphite liquor from an acidic or neutral cellulose sulphite cooking in an amount ranging from 10-90 percentage weight.
The additive is added to the compound feed in amounts ranging from 0,2 to 3,0%, preferably from 0,4 to 1,5%, and more preferably from 0,6 to 1,0%.
The following examples are meant to illustrate the invention without limiting its scope in any way.